2007 3.8L losing coolant
 

I've got a little mystery on my hands. My 2007 Unlimited Rubicon (with 48K miles) is losing coolant but I don't know where it's going. My overflow bottle has gone from MAX to just below MIN in 2,000 miles. It didn't used to do this. Nothing is dripping on the ground and I can find no visible evidence of a coolant leak.

Suggestions?

Thanks!

The mystery leak.There's some threads about this.Our's was the intake gasket at each end.It took some time before the leak would reach the ground

I had something like this happen. It ended up being the timing chain cover. A PITA to fix.

Attachment 501067

Could be a head gasket.

Augh! Don't say head gasket! That was the first thing I thought off. Engine runs fine though and there is no evidence of coolant in the oil (even on a 5,000 mile oil change schedule). The Jeep as sat for a week without a drip reaching the ground. I've looked around the engine and I don't see any discolorations or streaks where coolant could be leaking. That's why I'm so stumped.

With a head gasket leaking it can burn it in one of the cylinders. Normally you'll have steamy exhaust if that's the case.

That's bang on. If it's not on the ground or it's not making oil, it must be burning it.
Possibilities 1)bad head gasket 2)cracked head or 3)cracked block

Where's the heater core for the Jk? Some vehicles will leak coolant into the vehicle and u won't notice cause its under your carpet. I hope it's not ur head.

Yes, that's the only other place, except you'd smell it right away. Stinks up the cab and you fog up inside when you turn the heat on.
If ya know someone with a cooling system pressure tester, that's really the only method of tracking it down quickly.

Had the same problem this summer. Turned out to be a water pump. Eliminate the easy fix first, before losing sleep over cracked blocks and heads ;)